Answer:
H=10
Explanation:
First, let's find the area of the rectangle:
L*W
the length is 3 and the height is 10 so substitute and you get:
10*3 = 30
now let's find what the area of the triangle should be:
B*H/2 =30(because the area is the same)
the base is 6 and the height is unknown, now lets fully substitute:
6H/2=30
3H=30
H=10
Hope this helps :)